Author Topic: cylinder gaskets & Compresion?  (Read 313 times)

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Offline riverrocket

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cylinder gaskets & Compresion?
« on: January 08, 2013, 05:26:22 pm »
I Just rebuilt an 034S and I noticed that the Cylinder Gasket was kind of thick (Probably 3 cereal box Thickness) it was an OEM gasket, I thought i read somewhere, that Guys are using thinner, High Compression Gaskets or no gaskets at all just permatex.
i'm getting ready to rebuild an 036 now, and I'd like to experiment with increasing Compression, Maybe decking the cylinder.
What's your thoughts on this? If i Deck the Cylinder, how much should i shave off?
Do they sell thinner Cylinder gaskets? Thanks

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Offline 660magnum

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Re: cylinder gaskets & Compresion?
« Reply #1 on: January 08, 2013, 07:26:15 pm »
Watch your squish height.

Bolt the cylinder on with no ring with solder in just a little grease on four corners. Not too much grease or the solder might stick to the head and then fall out?

Turn the saw through top dead center and pull the cylinder - measure the thickness of the solder  (.020" minimum clearance between the edge of the head and the piston)

Use the small diameter electronic rosin core solder from radio shack.
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Offline Al Smith

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Re: cylinder gaskets & Compresion?
« Reply #2 on: January 09, 2013, 08:11:56 am »
FWIW the standard base gaskets on any Stihl I've worked on has been 20 thou thick .Now I've heard there were different thicknesses but I've never personally encountered any .

 I have however miscalculated the squish on several saws I modified and had to adjust same by cutting different thickness gaskets .

I prefer to use a base gasket but some have done well using some form of sealant and no gasket .I would speculate the sealant would pull down with around 2 thou thickness more or less so in theory you could drop the head deck heigth by around 18 thou .

I never measured the squish on an 036 but I'd guess around 45 thou stock so you could drop it by 18 thou and see some improvement .If it doesn't work put the gasket back in .

Offline 3000 FPS

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Re: cylinder gaskets & Compresion?
« Reply #3 on: January 12, 2013, 01:03:52 pm »
I have done a few saws eliminating the base gasket and using Yamabond to replace it.   I just finished up an 028 super for my BIL and eliminated the base gasket and took off a few more thousanths from the base.   I took it to a squish of .018.   I would probably not go that tight on a 036 being that it is bigger and could have more expansion when hot.   I ended up by the way with about 195 psi.
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Offline riverrocket

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Re: cylinder gaskets & Compresion?
« Reply #4 on: January 12, 2013, 06:47:55 pm »
Thanks for the help, the other day when I was ordering cylinder gaskets from my dealer, he asked me witch one i wanted the the thicker ones-1 mm or the thinner ones 1/2 mm.

Offline Al Smith

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Re: cylinder gaskets & Compresion?
« Reply #5 on: January 13, 2013, 06:54:29 am »
The .5mm would equate to 20 thou . I have no idea why they would offer 1 mm which would be 39 thou unless perhaps for lower octane gasoline if it exists some place .However it's a good thing to keep in mind for oafs like me who have a propensity to cut a tad too much off in a lathe if shaving the base .That fact to be quite truthfull I've done several times .

 

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